Add 1.0.3 changelog notes

Author: the-mikedavis

CHANGELOG.md

@@ -6,6 +6,14 @@ The format is based on [Keep a
 Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 1.0.3 - 2023-04-16
+
+### Fixed
+
+- Unexpected continuation frames are now handled.
+    - Previously, unexpected continuation frames received from a server
+      would result in a FunctionClauseError.
+
 ## 1.0.2 - 2022-12-11
 
 ### Fixed